diff options
Diffstat (limited to 'libgcc/config/libbid/bid32_to_bid128.c')
| -rw-r--r-- | libgcc/config/libbid/bid32_to_bid128.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/libgcc/config/libbid/bid32_to_bid128.c b/libgcc/config/libbid/bid32_to_bid128.c new file mode 100644 index 00000000000..1d47a5f519c --- /dev/null +++ b/libgcc/config/libbid/bid32_to_bid128.c @@ -0,0 +1,227 @@ +/* Copyright (C) 2007 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +In addition to the permissions in the GNU General Public License, the +Free Software Foundation gives you unlimited permission to link the +compiled version of this file into combinations with other programs, +and to distribute those combinations without any restriction coming +from the use of this file. (The General Public License restrictions +do apply in other respects; for example, they cover modification of +the file, and distribution when not linked into a combine +executable.) + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + +#define BID_128RES +#include "bid_internal.h" + +/* + * Takes a BID32 as input and converts it to a BID128 and returns it. + */ +TYPE0_FUNCTION_ARGTYPE1_NORND(UINT128, __bid32_to_bid128, UINT32, x) + + UINT128 new_coeff, res; + UINT32 sign_x; + int exponent_x = 0; + UINT32 coefficient_x = 0; + + if (!unpack_BID32 (&sign_x, &exponent_x, &coefficient_x, x)) { + if (((x) & 0x78000000) == 0x78000000) { + res.w[0] = 0; + res.w[1] = ((UINT64) (x)) << 32; + BID_RETURN (res); + } + } + + new_coeff.w[0] = coefficient_x; + new_coeff.w[1] = 0; + get_BID128_very_fast (&res, ((UINT64) sign_x) << 32, + exponent_x + DECIMAL_EXPONENT_BIAS_128 - + DECIMAL_EXPONENT_BIAS_32, new_coeff); + BID_RETURN (res); +} // convert_bid32_to_bid128 + + +/* + * Takes a BID128 as input and converts it to a BID32 and returns it. + */ +#if DECIMAL_CALL_BY_REFERENCE + +void +__bid128_to_bid32 (UINT32 * pres, + UINT128 * + px _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM + _EXC_INFO_PARAM) { + UINT128 x = *px; +#else + +UINT32 +__bid128_to_bid32 (UINT128 x _RND_MODE_PARAM _EXC_FLAGS_PARAM + _EXC_MASKS_PARAM _EXC_INFO_PARAM) { +#endif + UINT128 CX, T128, TP128, Qh, Ql, Qh1, Stemp, Tmp, Tmp1; + UINT64 sign_x, carry, cy; + SINT64 D; + UINT32 res; + int_float f64, fx; + int exponent_x = 0, extra_digits, amount, bin_expon_cx; + unsigned rmode, status; + +#if DECIMAL_CALL_BY_REFERENCE +#if !DECIMAL_GLOBAL_ROUNDING + _IDEC_round rnd_mode = *prnd_mode; +#endif +#endif + + BID_SWAP128(x); + // unpack arguments, check for NaN or Infinity or 0 + if (!unpack_BID128 (&sign_x, &exponent_x, &CX, &x)) { + if (((x.w[1]) & 0x7800000000000000ull) == 0x7800000000000000ull) { + res = ((UINT32) (x.w[1] >> 32)) & 0xfc000000; + BID_RETURN_VAL (res); + } + // x is 0 + amount = + exponent_x - DECIMAL_EXPONENT_BIAS_128 + DECIMAL_EXPONENT_BIAS_32; + if (((unsigned) amount) > DECIMAL_MAX_EXPON_32) { + sign_x >>= 32; + if (amount < 0) + res = sign_x; + res = + get_BID32 ((UINT32) (sign_x >> 32), DECIMAL_MAX_EXPON_32, 0, + rnd_mode, pfpsf); + BID_RETURN_VAL (res); + } + } + + if (CX.w[1] || (CX.w[0] >= 10000000)) { + // find number of digits in coefficient + // 2^64 + f64.i = 0x5f800000; + // fx ~ CX + fx.d = (float) CX.w[1] * f64.d + (float) CX.w[0]; + bin_expon_cx = ((fx.i >> 23) & 0xff) - 0x7f; + extra_digits = __bid_estimate_decimal_digits[bin_expon_cx] - 7; + // scale = 38-__bid_estimate_decimal_digits[bin_expon_cx]; + D = CX.w[1] - __bid_power10_index_binexp_128[bin_expon_cx].w[1]; + if (D > 0 || (!D && CX.w[0] >= __bid_power10_index_binexp_128[bin_expon_cx].w[0])) + extra_digits++; + + exponent_x += extra_digits; + +#ifndef IEEE_ROUND_NEAREST_TIES_AWAY +#ifndef IEEE_ROUND_NEAREST + rmode = rnd_mode; + if (sign_x && (unsigned) (rmode - 1) < 2) + rmode = 3 - rmode; +#else + rmode = 0; +#endif +#else + rmode = 0; +#endif + T128 = __bid_round_const_table_128[rmode][extra_digits]; + __add_carry_out (CX.w[0], carry, T128.w[0], CX.w[0]); + CX.w[1] = CX.w[1] + T128.w[1] + carry; + + TP128 = __bid_reciprocals10_128[extra_digits]; + __mul_128x128_full (Qh, Ql, CX, TP128); + amount = __bid_recip_scale[extra_digits]; + + if (amount >= 64) { + CX.w[0] = Qh.w[1] >> (amount - 64); + CX.w[1] = 0; + } else { + __shr_128 (CX, Qh, amount); + } + +#ifndef IEEE_ROUND_NEAREST_TIES_AWAY +#ifndef IEEE_ROUND_NEAREST + if (!(rnd_mode)) +#endif + if (CX.w[0] & 1) { + // check whether fractional part of initial_P/10^ed1 is exactly .5 + + // get remainder + __shl_128_long (Qh1, Qh, (128 - amount)); + + if (!Qh1.w[1] && !Qh1.w[0] + && (Ql.w[1] < __bid_reciprocals10_128[extra_digits].w[1] + || (Ql.w[1] == __bid_reciprocals10_128[extra_digits].w[1] + && Ql.w[0] < __bid_reciprocals10_128[extra_digits].w[0]))) { + CX.w[0]--; + } + } +#endif + +#ifdef SET_STATUS_FLAGS + + { + status = INEXACT_EXCEPTION; + // get remainder + __shl_128_long (Qh1, Qh, (128 - amount)); + + switch (rmode) { + case ROUNDING_TO_NEAREST: + case ROUNDING_TIES_AWAY: + // test whether fractional part is 0 + if (Qh1.w[1] == 0x8000000000000000ull && (!Qh1.w[0]) + && (Ql.w[1] < __bid_reciprocals10_128[extra_digits].w[1] + || (Ql.w[1] == __bid_reciprocals10_128[extra_digits].w[1] + && Ql.w[0] < __bid_reciprocals10_128[extra_digits].w[0]))) + status = EXACT_STATUS; + break; + case ROUNDING_DOWN: + case ROUNDING_TO_ZERO: + if ((!Qh1.w[1]) && (!Qh1.w[0]) + && (Ql.w[1] < __bid_reciprocals10_128[extra_digits].w[1] + || (Ql.w[1] == __bid_reciprocals10_128[extra_digits].w[1] + && Ql.w[0] < __bid_reciprocals10_128[extra_digits].w[0]))) + status = EXACT_STATUS; + break; + default: + // round up + __add_carry_out (Stemp.w[0], cy, Ql.w[0], + __bid_reciprocals10_128[extra_digits].w[0]); + __add_carry_in_out (Stemp.w[1], carry, Ql.w[1], + __bid_reciprocals10_128[extra_digits].w[1], cy); + __shr_128_long (Qh, Qh1, (128 - amount)); + Tmp.w[0] = 1; + Tmp.w[1] = 0; + __shl_128_long (Tmp1, Tmp, amount); + Qh.w[0] += carry; + if (Qh.w[0] < carry) + Qh.w[1]++; + if (__unsigned_compare_ge_128 (Qh, Tmp1)) + status = EXACT_STATUS; + } + + if (status != EXACT_STATUS) + __set_status_flags (pfpsf, status); + } + +#endif + + } + + res = + get_BID32 ((UINT32) (sign_x >> 32), + exponent_x - DECIMAL_EXPONENT_BIAS_128 + + DECIMAL_EXPONENT_BIAS_32, CX.w[0], rnd_mode, pfpsf); + BID_RETURN_VAL (res); + +} |